Rockwell Automation 1395 ControlNet Communication Board - Manual (Page 67)

6–3 Troubleshooting
Publication 1395.5.37 – March, 1999
Closed Connection – The drive is implemented as an adapter device on the
network and does not inititiate connections. One scanner device is allowed
to make a Class 1 connection to a drive. Many devices of various kinds can
open Class 3 connections to the drive at any time. When this happens, this
may be reported as a “Class 1 Close” or a “Class 3 Close”.
Connection Timeout – All connections, once opened, must be maintained
at some rate. If the drive does not receive data from from any open
connection within some period of time, a timeout condition is flagged. This
event can be reported as “Class 1 Timeout” or as “Class 3 Timeout”.
Controller Not in Run Mode – In addition to a loss of data due to network
errors or connections being lost, data may also be considered lost if the
controller goes out of run mode for any reason. Data being received from a
controller that is not in run mode is considered to be unreliable and is ignored
by the drive. The condition of a controller transitioning out of run mode can
be reported as “Reset/Prog/Test”.
Actions Resulting from Loss of Data – Any of the communication losses
described above can be handled in various ways. The condition can cause a
soft fault, which will cause a drive to stop active operation. The condition
can be reported as a warning which means the event is annunciated, but does
not change the running state of the drive. The condition may also be ignored.
Beyond this, the handling for the loss of the Class 1 I/O data can also be
configured with “Last State” bits that are defined in a subsequent section of
this document. These bits are used to define the action to be taken with the
Input image being used by the drive. This image can be either left in its last
received state or it can be zeroed. Loss of I/O image would occur for the
following conditions:
Reset/Prog/Test
ICN Comm Loss
Class 1 Close Class 1 Timeout
Parameters Relating to Communication Loss – Each drive has two
parameters that define how the communications losses get handled. These
parameters are called “ICN Fault Select” and “ICN Warning Select”.
Operation of bits within these parameters is essentially identical to similar
parameters used for RIO/DH+ adapters which exist at these parameter
numbers. Bit positions are identical for all of these parameters in a
ControlNet Adapter as detailed in the following table:
Bit Position Description
0 Reset/Program/Test
1 Last State
2 ICN Comm Loss
3 Class 1 Close
4 Class 3 Close
5 Class 1 Timeout
6 Class 3 Timeout